Air and gas mixer



March 4, 1941.

A. J. ROOT 2,233,677

AIR AND GAS MIXER Filed Aug. 30, 1939 Aug. 1.

2 Sheets-Sheet 1.

Jig. Z.

[NVENTOR rf/wr J Root A T'TORNE Y A. J. ROOT 2,233,677

AIR AND GAS MIXER March 4, 1941.

2 Sheets-Sheet 2 Filed Aug. 30, 1939 11v VENTOR flrf/rur J Roof Patented Mar. 4, 1941 UNITED STATES PATENT OFFICE AIR AND GAS MIXER Arthur I. Root, Quapaw', Okla. Application August 30, 1939, SerialNo; 292,647

4 Claims.

lhis invention relates to air and gas mixers, particularly those for use in connection with internal combustion engines, and has for its principal object to provide a device of this character arranged for maintaining an efiicient air and gas mixture responsive to suction of the engine with which-it is connected.

It is also an object of the-invention to provide an air and gas mixer with a throttle valve acting independently of the usual governor actuated throttle valve, so that the engine is started under control of a manually-operated throttle and thereby avoid starting of the engine under wide open throttle conditions.

Other objects of the invention are to provide a gas, mixer with a piston or sleeve-type valve having air inlet ports in the headthereof normally closed when the gas inlet port thereof is out of registry with the gas supply port; to provide a construction wherein a portion of gas is trapped within the mixer and which is immediately available upon restarting the engine; to provide an air and gas mixer with manual means for initially actuating the piston valve thereof; to

provide an improved gas shut-off valve in cooperation-with the mixer; to provide an air and gas mixer adapted for connection to the air intake of a conventional carburetor; to provide a combination mixer and carburetor using the carburetor throttle valve for controlling operation of the mixer; to provide a combination gasoline carburetor and air and gas mixer capable of selectively operating an engine on either gas or gasoline; and to provide an air and gas mixer which is of simple and inexpensive construction.

In accomplishing these and other objects of the invention, I have provided improved details of structure, the preferred forms of which are illustrated in the accompanying drawings, wherein:

Fig. 1 is a side elevational view of an air and gas mixer and its associated valve for controlling admission of gas thereto.

Fig. 2 is a vertical section through the mixer on the line 2-2 of Fig. 1, particularly illustrating 5 the throttle valves and the pistontype mixing valve for controlling admission of air and gas.

Fig. 3 is a plan view of the apparatusshown in Fig. 1.

Fig. 4 is a detail section throughthe adjustable so stop on the gas shut-off valve.

Fig. 5*is a cross-section through the mixer on the line 5-5 of Fig. 1.

Fig. 6 is a detail perspective view of the piston type valve and. valve plate for closing off admission of air'into the-mixer.

Fig- 7 is-a side elevational view of the mixer as applied to'the air inlet of a carburetor, thereby adapting the mixer to an engine designed for operation on liquid fuel.

Fig. 8 is a vertical section through the mixer on the line 8-8 of Fig. 7, particularly showing attachment of a mixer to the air inlet of the carburetor.

Referring more in detail to the drawings:

I designates an air and gas mixer constructed 10 in" accordance with the present invention, and includes a casing 2 having av substantially cylindrical body portion 3 provided with a lateral gas in let connection 4 and a lower throttle portion 5, of slightly smaller diameter than the cylindrical 15 body portion 3 to provide an annular stop shoulder 6 therebetween. Theportion 5 has a neck I provided with a flange 8 for connection with the inlet 9 of an engine manifold II] by means of fastening devices, such as cap-screws I I. 20

The form of the invention illustrated is adapted for connection with a manifold having passages I2 and I3 leading to separate lines of cylinders in a multi-cylinder engine (not shown), and therefore the neck I has diverging branches I4 25 and I5'leading to the respective passages I2 and I3. The branches I4 and I5 are provided with throttle valves I6 and I1 fixed to a common shaft I8 extending. diametrically thereacross and having. its ends journalled in bearings I9 and 20 30 formed as an integral part of the flange 8.

The shaft I8 is usually controlled by a governor (not shown) and actuated responsive to speed of the engine, the governor being connected with a lever arm. 2I fixed to the outer end of '35 the shaft as in conventional practice. In ordinary installations the governor is so arranged that when the engine is idle the throttle valves I6 and I! are wide open, and when the engine is started the valves are automatically moved toward closed position in accordance with the setting of the governor, whereby the engine is caused to maintain a constantly uniform maximum speed.

The cylindrical body portion 3 is provided at the top thereof with an opening 22, encircled by 5 a flange 23. upon which the flange 24 of a collar 25 is retained by cap-screws 26. The collar 25 has an externally grooved neck: portion 21 for attaching an air cleaner or the like (not shown). Formed in the upper face of the flange 23 is an inset shoulder or seat 28, mounting a valve plate 23 that is clamped therein by the flange 24. The plate v29 includes oppositely disposed sectorshaped segments 30 and 3| formingl'sector-shaped air inlet openings 32 and 33 therebetween. The 55 segments 36 and 3| are interconnected by an integral collar 34, having a bearing opening 35 therein for a purpose later described.

With the structure thus far described it is obvious that air may be drawn through the collar 25 and through the sector-shaped openings or a suitable source of gas supply (not shown). The

valve 39 may be of conventional construction,

but the stem 4| thereof projects through the top" vthe butterfly type and is mounted on a shaft 69 of the casing and is provided with an opening 42 through which an actuating lever or rod 43 is extended. The end 44 of the lever terminates in anofisetadapted to engage an adjustable stop 45. The stop 45 is in the form of a C-clamp as shown in Fig. 4, and is clamped in. a selected position about the periphery of a laterally propiston type valve 48, including a skirt portion 49v movable in sliding contact with the inner face 50 of the casing, and a head 5| that is provided with sector-shaped openings 52 and 53 therein registering with the sector-shaped segments 30 and 3| of the valve plate previously described.

Fixed. within a concentric opening 54 in the center of the head isa stem 55, slidable through the bearing opening 35, and which carries a coil spring 56 sleeved thereover, having one end bearing against the collar 34 and its opposite end against a washer 51 retained on the upper end of the stem by a cotter pin 58, as shown in Fig. 2. The skirt portion of the valve is open at the lower end and in direct communication with the throttle valve 59 in the portion 5 of the casing. The skirt portion of the valve has a gas inlet port 66 extending therethrough and which is located in upward ofiset relation with the gas inlet port 33 when the head of the valve is engaging the.

valve plate29. The piston-like valve is retained from rotation within the cylindrical portion of the casing by a set-screw 6|, threaded in the side of the casing and having its end projecting through a vertical slot 62 in the skirt of the valve as shown in Figs. 2 and 5.

The spring 56 is so adjusted that the openings 52 and 53 of the head are normally closed by the sector-shaped segments 39 and 3| of the valve plate, and the port is out of registry with the gas inlet opening so that when the engine is idle the gas and air inlet ports are closed.

In order to initially open the air and gas ports, for starting of the engine, the collar 25 carries a manually-operated lever 63 that is pivoted on a pin 64 extending transversely through a slot 65 in the collar. The inner end of the lever curves downwardly, as at 66, to engage the head of the piston-like valve, while the opposite end projects through the slot of the collar to form a handle 61 by which the lever may be manipulated to move the piston-like valve downwardly within its cylindrical chamber to uncover the ports 52 and 53 and to bring the gas inlet port 60 into partial registry with the gas inlet port 36. Gas and air are then being admitted to the interior of the piston-like valve to form a combustible mixture which is drawn through the intake manifold connections of the engine.

With the structure thus far described it is obvious that the engine would be started on wide open throttle, and to avoid this difficulty the portion 5 of the housing is provided with a throttle valve 59 which is normally closed and adapted to be gradually opened to control admission of the combustible mixture into the engine, until en'gine'at a constant speed. The valve 59 is of extending transversely of the casing and having its ends journalled in bearings 16 and II formed in the walls thereof as shown in Fig. 2. The end of the shaft projecting through the bearing l6 carries an actuating lever 12, having a spingpressed pawl 13 on the side thereof and which is adapted to engage in one of a series of notches 14 formed in aboss-like segment 15 on the side 01" the mixer casing, as shown in Fig. 2. The valve 59 may thus be retained at any one of a plurality of positions as governed by the notches 14. The opposite end of the shaft carries a stop lever 76 having an arm 11 engageable with a laterally projecting shoulder 19 on the side of the casing portion 5.

In assembling a mixer, the piston-like Valve 48' is inserted through the open top of the casing,

are registered with the closure segments 30 and 3i 'of the valve plate and retained by application of the set-screw 6| so that the end thereof passes into the vertical guide slot 62. The mixer casing carrying thethrottle valve 59 is then attached to the-inlet connection of the manifold, after which the gas connection carrying the valve 39 is attached to the part 4 of the air and gas mixer. v

. When the engine is to be started, the manual lever 63 is operated to depress the piston-like valve against action of its spring, as shown in Fig. 2. Upon cranking of the engine, air is drawn through the collar, ports 32 and 33, ports 52 and 53,- intorthe interior of the piston-like Valve. Simultaneously gas is drawn through the partially registering ports 36 and 66 for mixture with the air. The; mixture is then drawn into the intake passages l2 and I3 undercontrol of the manually-actuated throttle valve 59.

When the engine gets under way, the suction created in the passageways l2 and I3 maintains thepistonlike valve in open position. As the'engine gradually increases in speed, the suction increases so that the piston valve is moved toward full opening of the port 60 and the air inlet ports, thereby maintaining the air and gas mixture at proper-ratiof As the engine speed is reduced and the suction becomes less, the spring 56 preponderates to move the piston-like valve toward" closed position, thereby maintaining the proper gas and air ratio for the reduced engine speed. When the engine is stopped, the head of the piston-like valve is drawn against the valve plate to shut off the air supply and at the same time the gas inlet port 60 is moved out of registry with the port 36 to trap an air and gas mixture within the mixer upon closure of the Valve 59. This air and gas mixture is immediately available upon restarting of the engine.

The form of mixer shown in Figs. 7 and 8 is identical to that illustrated in the preferred form,

with the exception that the lower portion of the housing which carries the valve 59 is provided with an annular depending collar engageable over the air inlet connection 8! of a conventional carburetor 82 and secured by set-screws 83. In this instance the governor-actuated throttle valve, as in icated by the lever 84, is the conventional throttle, and is a part of the carburetor. The carburetor is normally supplied with gasoline by a line 85 having a valve 86 therein so when it is desired to operate the engine on gas the valve 86 is closed and the combination carburetor and mixer operates in the identical manner as the air and gas mixer above described.

However, if it is desirable to operate the engine on gasoline the valve 86 may be opened and the valve 39 closed so the combination acts as a conventional carburetor thereby permitting the engine to operate on either gas or gasoline Without changing the assembly.

From the foregoing it is obvious that I have provided an air and gas mixer which is of simple construction and well adapted for the eflicient mixture of air and gas supplied to the intake manifold connections of an internal combustion engine.

What I claim and desire to secure by Letters Patent is:

1. An air and gas mixer for an internal oombustion engine including, a casing having a sub-. stantially cylindrical wall provided with a gas inlet spaced from the ends thereof and having an end wall provided with an air inlet opening, a piston-like valve having a cylindrical skirt portion closely contacting the cylindrical wall of the casing to maintain said valve in coaxial relation therewith and having a head adapted to abut against the end wall of the casing to close said air inlet opening, the head of said piston-like valve having an opening ofiset from said air inlet opening for admitting air to the lower portion of the casing when the piston-like valve is moved from abutting relation with the end wall, said skirt portion of the piston-like valve having an opening registrable with the gas inlet when the piston-like valve is moved from closing relation with respect to said air inlet opening, means yieldingly retaining the piston-like valve in position to close said inlets, and means for moving the piston-like valve to open said inlets.

2. An air and gas mixer for an internal combustion engine including, a casing having a substantially cylindrical wall provided with a gas inlet spaced from the ends thereof and having an end Wall provided with an air inlet opening, a piston-like valve having a cylindrical skirt portion closely contacting the cylindrical wall of the casing to maintain said valve in coaxial relation therewith and having a. head adapted to abut against the end wall of the casing to close said air inlet opening, the head of said piston-like valve having an opening ofiset from said air inlet opening for admitting air to the lower portion of the casing when the piston-like valve is moved from abutting relation with the end wall, said skirt portion of the piston-like valve having an opening registrable with the gas inlet when the piston-like valve is moved from closing relation with respect to said air inlet opening, means yieldingly retaining the piston-like valve in position to close said inlets, means for moving the piston-like valve to open said inlets, and means for preventing rotation of the piston-like valve to maintain ofiset relation of the head opening with the air inlet opening and to maintain alignment of said skirt opening with the gas inlet.

3. An air and gas mixer for an internal combustion engine including, a casing having a substantially cylindrical wall provided with a gas inlet spaced from the ends thereof and having an end wall provided with an air inlet opening, a piston-like valve having a cylindrical skirt portion closely contacting the cylindrical wall of the casing to maintain said valve in coaxial relation therewith and having a head adapted to abut against the end wall of the casing to close said air inlet opening, the head of said piston-like valve having an opening offset from said air inlet opening for admitting air to the lower portion of the casing when the piston-like valve is moved from abutting relation with the end wall, said skirt portion of the piston-like valve having an opening registrable with the gas inlet when the piston-like valve is moved from closing relation with respect to said air inlet opening, a gas supply duct connected with the gas inlet, means yieldingly retaining said valve in position to close said inlets, means for moving the valve to open said inlets and a stop valve in said duct.

4. An air and gas mixer for an internal combustion engine including, a casing having a substantially cylindrical wall provided with a gas inlet spaced from the ends thereof and having an end wall provided with an air inlet opening and an axial guide opening, a piston-like valve having a cylindrical skirt portion closely contacting the cylindrical wall of the casing to maintain said valve in coaxial relation therewith and having a head adapted to abut against the end wall of the casing to close said air inlet opening, a stem fixed to the head of the piston-like valve in the axis thereof and movable through the axial guide opening to cooperate with said skirt portion to maintain said coaxial relation, a spring sleeved over the stem for normally retaining the head of the piston-like valve in abutting contact with said end wall to close said inlets, the head of said piston-like valve having an opening offset from said air inlet opening for admitting air to the lower portion of the casing when the piston-like valve is moved from abutting relation with the end wall, said skirt portion of the piston-like valve having an opening registrable with the gas inlet when the piston-like valve is moved from closing relation with respect to said air inlet opening, and a lever for moving the piston-like valve against action of said spring to open said inlets.

ARTHUR J. ROOT. 

